The present invention generally relates to a socket cover that is cam actuated. More particularly, the present invention relates to a socket cover having a cover plate configured to absorb torque induced by cam rotation.
Many large electronic devices, such as computers, use sockets to connect different electronic components. For example, pin grid array (PGA) sockets are used to connect electronic packages, such as processors, to printed circuit boards. PGA sockets facilitate electrical communication between a large number of pins on the processor and contacts on the circuit board. PGA sockets may utilize a plastic socket cover that is slidably movable on a plastic socket base between open and closed positions. Generally, a cam mechanism is used to drive the cover and base between open and closed positions.
The socket cover has an array of pin holes configured to match an array of pins on the processor. Similarly, the socket base has an array of pin receiving chambers configured to accept the array of pins on the processor and connected to contact pads on the circuit board. The processor is mated to the socket by first placing the processor such that its pins slide into the pin holes of the socket cover. With the socket cover in the open position, the processor pins pass through the pin holes of the socket cover into the pin receiving chambers of the socket base, but are not yet electrically connected to the pin receiving chambers of the socket base. A cam mechanism on the socket is rotated to slide the socket cover to the closed position which causes the processor pins to electrically connect to contacts in the pin receiving chambers in the socket base.
The cam mechanism includes a plate that is retained in a recessed area on the bottom of the socket cover between the socket cover and the socket base. The socket cover, plate, and socket base each have apertures therethrough that align with one another to receive a cam shaft. The cam shaft is situated in a channel on the socket cover and extends through the socket cover, plate and socket base. The cam shaft is rotated to slide the socket cover to the closed position on the socket base to electrically connect the processor pins to contacts in the pin receiving chambers in the socket base. More specifically, as the cam shaft is rotated to cause the sliding movement between the socket cover and socket base, the cam shaft drives the plate relative to the socket base. The plate is held firmly in the recessed area in the socket cover which in turn causes the socket cover to move relative to the socket base. The plate is used to absorb the torque forces created by the cam shaft to prevent the socket cover from cracking.
However, the conventional sockets suffer from several drawbacks. As the cam shaft rotates, it generates torque forces. As noted above, the plate is positioned in the recessed area of the socket cover to absorb much of the torque forces and distribute the torque forces throughout the plate in order to prevent the torque forces from cracking the thin plastic socket cover. However, the torque forces cause the plate to twist or “rotate” within the recessed area such that certain angled points on the plate press directly against the wall segments of the socket cover. Thus, the torque forces are redistributed at high stress concentrations at certain points along the wall segments which cause strains and cracks in the socket cover to develop over time with repeated use. Once cracks occur in the socket cover, the plate moves relative to the socket cover thereby reducing the amount of motion transferred from the cam to the socket cover. Hence, the cam shaft cannot properly engage the socket cover to slidably move the socket cover the full desired distance relative to the socket base.
A need exists for a socket cover that addresses the above noted problems and others experienced heretofore.